3:5 divider on X38/P35/X48/P45 is broken, is 2:3 in reality on 400 strap

[Gautam]

Needs a thread of it's own for a bit, IMHO

Hi, Bros,

3:5 400mhz Strap of all intel chipset is incorrect. due to chipset divider limit
for other strap (200/266/333) 3:5 runs correct ratio & frequency.

3:5 400 Strap should be 2:3, not 3:5
if you are running 600Fsb and chosen divider of 3:5 400 Strap
Frequency of memory is 900mhz(DDR3-1800), if 650FSB,mem is 975mhz

Hicookie

[3oh6]

thanks Gautam, we both knew that's what it was...confirmation is nice though.

[eva2000]

has same on DFI UT X48-T3RS with 400/1333 at first DFI said it's incorrect and should be 400/1200 but then subsequently it is 400/1333 http://i4memory.com/showthread.php?t=6657

could explain low performance on 400/1333 http://i4memory.com/91204-post9.html

[BulldogPO]

This should be also on news section.
We do need someone from Intel to comment this.

[[XC] gomeler]

Just means I have more room to overclock above 600FSB and the "3:5" divider

[Rol-Co]

More room gomeler but worse performance.

ran 620 3:5 400 strap (1033 memory) but notish no difference in performance over 2:3 on auto strap.(930 memory)
strange thing is i need more voltage on the memory to do this though.

[thorgal]

Saw exactly this on the Asus P5Q3 in my latest memory (OCZ Flex II) review. Nice to see it confirmed.

[hiwa]

thanks guantum i confirm it

this is my test

boot@600
strap :400
dram freq : 1800
and cpuz in win says

[ToyTen]

This is on Evolution X48:


cpu-z 1.45 reads it correctly.

Same situation on X48 p5e3 Premium